Le Jeu de Go

Le Jeu de Go

 

Go
Un goban traditionnel de go, avec des pierres en noir et blanc.
Nom japonais
Kanji

Originaire de Chine, le jeu de go (ou igo en japonais formel) oppose deux adversaires qui placent à tour de rôle des pierres noires (kuro) et blanches (shiro) sur un tablier, appelé goban, tentant ainsi de contrôler le plan de jeu en y construisant des « territoires » qui se comptent en moku. Chaque « pierre » représente un soldat ; les soldats encerclés deviennent des prisonniers.

Il s’agit du plus ancien jeu de stratégie combinatoire abstrait connu. Malgré son ancienneté, le jeu de go continue à jouir d’une grande popularité en Chine, en Corée et au Japon. Dans le reste du monde, où sa découverte est récente, sa notoriété est croissante. Son succès tient autant à la simplicité de ses règles qu’à sa grande richesse combinatoire et sa profondeur stratégique.

La terminologie du go est principalement d’origine japonaise. En cas de difficulté, se rapporter au lexique du jeu de go.

Sommaire

La très longue histoire du go s’est déroulée pour une grande part dans des mondes clos et séparés : en Chine d’abord, puis au Japon, et enfin en Occident. C’est seulement depuis la fin du XXe siècle que le go commence à s’unifier sur le plan international.

Un jeu chinois

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Jeu de go au XVIe siècle. Détail des « Quatre accomplissements » par Kano Eitoku.

Légendes des origines

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Selon une tradition chinoise, ce serait deux dragons appelés Hei-Zi (le noir) et Bai-Zi (le blanc) se disputant pour savoir lequel des deux était le plus puissant qui créèrent le wéiqí (nom chinois du go) pour se départager. Les dieux envoyèrent alors un troisième dragon observer la partie et lui ordonnèrent de ne revenir faire son rapport qu’une fois celle-ci terminée. Leurs règles étaient les mêmes que les nôtres aujourd’hui, si ce n’est que la règle du ko n’existait pas puisque, étant immortels, ils étaient infiniment patients. Les dragons jouent donc depuis des milliers d’années et chaque millénaire, les dieux envoient un nouvel observateur. Actuellement, cinq dragons observent le jeu, et un sixième devrait être envoyé dans quelques années.

Sur le plan historique, bien que le wéiqí soit très ancien, les datations qui lui attribuent plus de 4 000 ans d’âge ne reposent que sur des récits légendaires que rien ne vient étayer mais que beaucoup ont pris pour argent comptant. Seule certitude, le jeu fut inventé bien avant notre ère en Chine. Son attribution à l’un ou l’autre des empereurs légendaires Yao ou Shun, chacun l’ayant utilisé pour l’éducation de leur fils, n’a aucun fondement historique. Pas plus d’ailleurs qu’une autre légende qui en attribue l’invention à un vassal, s’appelant U, qui l’aurait imaginé, quant à lui, pour distraire son suzerain sous le règne de Jie Gui au XVIIe siècle av. J.-C. Certains chercheurs voient dans l’art divinatoire chinois du Yi Jing de nombreuses analogies avec le wéiqí qui pourrait en être le vecteur matériel.

Premières attestations

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On trouve les premières références écrites à un jeu qui pourrait être le go dans les Annales des Printemps et des Automnes (entre 722 et 481 av. J.-C.). Plus tard, Confucius mentionne le go dans ses entretiens. Le jeu connaît alors un très fort développement avec l’apparition d’un système de classement des joueurs, d’instituts de go et de fonctionnaires. Les livres se multiplient : recueils de parties, écrits théoriques, listes de joueurs, etc. Les premiers traités de go sont écrits à la fin de la dynastie Han (début du IIIe siècle ap. J.-C.). Le go est alors intégré aux « trois arts sacrés » ( peinture, musique et calligraphie) pratiqués par l’empereur et ses courtisans ; cela durera jusqu’à la fin du XIXe siècle. Dès la fin des Han et jusqu’à la restauration de l’empire par les Sui en 589 ap. J.-C., les classes dirigeantes sombrent dans le désœuvrement et se tournent vers le taoïsme et le go.

Un jeu japonais

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Le wéiqí arrive en Corée au Ve siècle et atteint enfin l’archipel nippon où il est vite adopté par l’aristocratie locale, très influencée par la Chine. Selon la tradition, c’est en 735 que le go fut introduit au Japon mais on trouve des interdictions du go déjà édictées plusieurs dizaines d’années plus tôt. Dans un décret de l’impératrice Jito promulgué en 701, l’aristocratie s’arroge le droit d’y jouer. Les moines bouddhistes, auxquels on interdit la musique et les jeux de hasard obtiennent le droit de jouer au go, non considéré comme un jeu de hasard. Réservé à l’élite sociale, le go ne s’est cependant pas démocratisé au Japon avant le XXe siècle. La pratique du go se généralisera parmi les samouraïs comme entraînement à la stratégie militaire. À Kyoto, les moines nichirens ( secte bouddhiste japonaise) seront les fondateurs d’ Honinbo, la première grande école de go qui durera jusqu’en 1940. Au XVe siècle, une simple modification de règles va transformer profondément la pratique du jeu. On abolit la règle du zuozi qui consiste à placer une pierre dans chacun des quatre hoshi de coin du goban et on commence désormais la partie avec un goban entièrement vide. Le zuozi restera en vigueur en Chine jusqu’au début du XXe siècle. Au Japon, le go est désormais libre pour les explorations théoriques sans entrave qui déboucheront sur le développement des fuseki et des joseki.

Âge d’or du go

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Geisha jouant au go

Dans la seconde moitié du XVIe siècle, le go est objet de grand intérêt de la part des seigneurs qui se disputent le pouvoir. En 1578, le daimyo Oda Nobunaga invite à Edo le moine Nikkai, un joueur réputé, pour l’affronter. Impressionné par la force de Nikkai, il lui accorde le titre de Meijin (Maître) qui deviendra par la suite l’un des grades les plus prestigieux du monde du go. Nikkai est nommé instructeur d’ Oda Nobunaga. Quelques années plus tard, en 1582, celui-ci assiste à une partie dans laquelle apparait un triple ko. Le soir même, l’un de ses compagnons d’arme se révolte, provoquant le seppuku d’ Oda Nobunaga. Depuis, le triple ko est considéré comme un présage néfaste. En 1590, Toyotomi Hideyoshi organisa le premier tournoi officiel pour désigner le plus fort joueur du pays. Honinbo Sansa (nouveau nom de Nikkai) remporta ce premier titre. Les autres joueurs sont classés en fonction de leur rang selon le système nouvellement créé des dan. Avec l’unification du Japon par Ieyasu Tokugawa en 1603, le go, soutenu par les militaires et le shogunat Tokugawa, entre dans sa période classique et connaît un développement ininterrompu pendant plus de deux siècles et demi. Grâce à la protection du shogun, le go acquiert un statut officiel et devient une institution gouvernementale. Le meilleur joueur du pays se voit promu au rang de godokoro, une sorte de « ministre du go » qui a la haute main sur toute l’administration du go professionnel. Trois nouvelles grandes écoles voient le jour, Hayashi, Inoue et Yasui, qui disputeront la prééminence à la prestigieuse Honinbo. Elles s’affronteront pour se partager les prébendes et les postes de fonctionnaires richement dotés. Un tournoi annuel (o-shiro-go) réunira les deux meilleurs joueurs en présence de l’ empereur et du shogun. En 1868, la restauration Meiji mettra un terme à cet âge d’or. Avec l’entrée du Japon dans l’ère industrielle, le go perd ses repères féodaux traditionnels et ses mécènes, et il sombre dans une crise durable et profonde. Plusieurs tentatives de réorganisation avortent rapidement. En 1879 cependant est fondé Hoensha, la première organisation qui parvient à fédérer le monde du go. Après de nombreuses vicissitudes, il en émergera la Nihon Ki-in fondée le 20 mai 1924. Les premières décisions de ces organisations visent à démocratiser le go. Grâce à la couverture régulière dont il est l’objet dans certains journaux comme le Daily Yomiuri, le go devient très populaire. C’est aussi à ce moment que sont édictés les premiers règlements concernant les cadences de jeu : en 1922, le temps total dont dispose chaque joueur est réduit à 16 heures. Il n’était en effet pas rare à l’époque qu’une partie durât une semaine ou plus ; certaines parties furent interrompues jusqu’à 20 fois. Le roman de Kawabata, Le Maître, ou le Tournoi de go, met en scène l’ultime partie de Shusai, dernier des Honinbo, jouée contre Kitani Minoru (appelé Otake dans le livre), et qui fut aussi la dernière de ces parties interminables : « Les joueurs de haut rang se voient généralement attribuer dix heures chacun pour une partie, mais cette fois, par exception, les délais avaient été multipliés par quatre. Il restait encore quelques heures aux Noirs, néanmoins, trente-quatre heures, cela semblait tout à fait inhabituel, et même sans doute unique dans les annales du jeu, depuis qu’on fixait des limites de temps.  ». La partie en question, qui se déroule en 1938, s’étale sur six mois et quatorze séances. La première séance, cérémonie d’inauguration, ne comprit, pour la forme, que les deux premiers coups. La durée des parties sera encore réduite par la suite.

Le go à l’ère atomique

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Le go continua son chemin malgré toutes les difficultés inhérentes à la Seconde Guerre mondiale. Une anecdote illustre bien la rage de jouer des professionnels du go. Au printemps 1945, Iwamoto Kaoru devint challenger d’ Hashimoto Utaro dans le prestigieux tournoi d’ Honinbo. Jouer à Tokyo étant impensable après les terribles bombardements de mars 1945, il fut décidé que le match se déroulerait durant l’été à Hiroshima. La première partie eut lieu les 23 et 25 juillet 1945 malgré l’interdiction de jouer signifiée aux joueurs par le chef de la police locale qui craignait pour leur sécurité. Leur maison fut d’ailleurs mitraillée par l’ aviation américaine durant la partie. Furieux d’apprendre qu’on avait enfreint ses ordres, le policier leur interdit formellement de rejouer dans la ville. Les adversaires tombèrent d’accord pour disputer 6 août à Itsukaichi dans la banlieue d’ Hiroshima. Au troisième jour du match, les joueurs faisaient une pause dans le jardin, lorsqu’ils aperçurent une explosion fulgurante suivie par la formation d’un gigantesque « champignon » et par un coup de vent violent qui brisa les fenêtres et renversa les meubles et la table de jeu. Comme ils en étaient au yose (fin de partie après les combats), ils replacèrent la position et terminèrent la partie (qui se finit par une victoire de Hashimoto avec cinq points d’avance). Ce ne fut que plus tard dans la journée, en voyant arriver les rescapés de la première bombe atomique, que les joueurs comprirent la tragédie à laquelle ils avaient miraculeusement échappé. Le match se termina par un résultat nul (3-3) en novembre 1945, durant l’ occupation américaine après la reddition du Japon.

Diffusion en Occident

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La découverte du go en Europe fut extrêmement tardive. Ce n’est qu’au XVIIe siècle qu’apparaissent les premières mentions du jeu de go. La première attestation écrite remonte à la traduction, publiée en 1615 à Augsbourg, du récit du séjour en Chine du jésuite Matteo Ricci. Par la suite, les mentions du go se multiplient à travers l’Europe mais toujours assez brièvement dans des récits de voyage. Il faut attendre 1710 pour que Gottfried Wilhelm von Leibniz rédige les premières considérations mathématiques sur le go. Selon Franco Pratesi, les premières descriptions du jeu étaient cependant trop sommaires pour pouvoir y jouer correctement. C’est seulement à la fin du XIXe siècle que le sinologue anglais Herbert Giles donne la première présentation utilisable des règles du jeu de go ainsi que des conseils au débutant (comme celui d’utiliser un goban de 11×11, etc). À la même époque, l’Allemand Oskar Korschelt – qui a passé plusieurs années au Japon en tant que dentiste, et a eu le 18e Honinbo, Shuo, comme patient – publie plusieurs articles puis un livre Das japanisch-chinesisch Spiel ‘Go’ : ein Concurrent des Schach ( 1881) qui auront un impact décisif sur la découverte du go : le jeu connaîtra alors ses premiers développements, principalement en Allemagne (en particulier à Leipzig) et en Autriche-Hongrie (à Vienne et Graz). Le premier club est créé en 1895 à Pola par des officiers de la marine austro-hongroise et la première revue, la Deutsche Go-Zeitung, naît à Vienne en 1909. Par la suite, le go prend racine à Berlin avec quelques joueurs célèbres (Max Lange, un homonyme du joueur d’échecs, Edward Lasker, Emanuel Lasker, etc). En août 1924, se déroule à Munich le premier tournoi allemand.

Le go moderne

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Après la Seconde Guerre mondiale, le go se développe sous l’impulsion de la fédération japonaise (Nihon Ki-in). En Chine où il végétait depuis des siècles, le jeu de go, après avoir surmonté la crise de la Révolution culturelle, connaît un renouveau spectaculaire depuis les années 1980 et un développement sans précédent. Dans les années 1990, c’est au tour de la Corée d’entrer en scène avec de très forts joueurs, comme Lee Chang-ho considéré alors comme le meilleur joueur du monde. De fait, à la fin des années 1990, les trois meilleurs joueurs coréens se sont adjugés, à eux seuls, près de 50% des titres internationaux. Le Japon, qui régnait sans partage sur le monde du go depuis des siècles, voit sa suprématie bousculée et maintenant remise en question tous les ans. À travers le go, les trois pays de l’ Asie de l’Est ont trouvé une nouvelle occasion -pacifique- de vider leurs querelles historiques. Dans le reste du monde, l’intérêt pour le go s’est constamment développé mais à un rythme moins soutenu, souvent au travers de la diaspora chinoise, coréenne ou japonaise. Ainsi, en France, le jeu a connu un important développement à partir de 1969, dû presque uniquement à la présence d’un fort joueur amateur coréen, Lim Yoo Jong. Il faudra attendre 1978 pour voir un Européen obtenir un titre professionnel de go et 2000 pour qu’un Occidental obtienne un rang de neuvième dan. En Europe, le plus fort joueur professionnel est actuellement le Chinois Fan Hui, arrivé en France en 2000. Aujourd’hui, on compte plus de quarante millions de joueurs dont un million d’Européens. La parution du manga Hikaru no go, à la fin des années 1990, a ravivé l’intérêt pour ce jeu, notamment chez les jeunes; la même période voit l’apparition de serveurs dédiés au go (KGS et IGS sont sans doute les plus populaires actuellement en Occident), ce qui permet désormais à tous de jouer à toute heure, et d’observer des parties de tout niveau, amenant à une forte augmentation du nombre des joueurs confirmés, et à une accélération de leurs progrès.

Matériel de jeu

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Équipement traditionnel de go

Le matériel du jeu de go est extrêmement simple. Il a pourtant donné lieu à des productions artistiques très élaborées : matériaux précieux, décorations soignées, etc. Aujourd’hui encore, on produit de tels équipements traditionnels qui atteignent des prix astronomiques. Mais la démocratisation du go permet désormais de trouver partout des équipements simples et bon marché.

Goban

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Une partie de go se déroule sur un tablier, le goban, sur lequel est tracée une grille de 19 lignes horizontales par 19 lignes verticales qui déterminent 361 intersections. Ce nombre de lignes est parfois réduit (souvent ramené à 13×13 ou 9×9 lignes) pour jouer des parties rapides ou pour faciliter l’apprentissage des règles du jeu. Il y a aujourd’hui une tendance à valoriser le jeu sur ces petits goban.

Pierres

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Les deux adversaires placent des pions noirs et blancs, appelés pierres (go-ishi), sur une intersection du goban. En théorie, ils disposent d’un nombre illimité de pierres, autant qu’il en faut. Les équipement vendus dans le commerce se limitent généralement à 180 pierres noires et 180 pierres blanches, nombres qui sont très proches de la moitié du nombre d’intersections sur le goban (361). En pratique, il est très rare qu’une partie dépasse trois cents coups ; de plus, en cas de besoin, il est le plus souvent possible de procéder à des échanges de prisonniers. Dépourvues de toute inscription ou décoration, les pierres ont toutes la même forme, et ne se différencient que par la couleur. Leur forme est généralement celle de lentilles biconvexes ou plan-convexes (pierres Yunzi par exemple). Les pierres traditionnelles de luxe étaient en ardoise pour les pierres noires et en coquillage pour les pierres blanches. Aujourd’hui, le matériau le plus courant est le verre coloré mais on en trouve en différentes autres matières : plastiques, bois, mais aussi jade, agate et autres pierres semi-précieuses.

Bols

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Les pierres sont conservées dans des bols (go-su ??) dont les couvercles peuvent servir à recueillir les prisonniers. Les bols ont également donné lieu à des productions de qualité extrêmement variée (allant du bois précieux au simple plastique).

Horloge

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Depuis les années 1920, le temps imparti pour la partie est limité et contrôlé par une horloge. Traditionnellement, dans les grands tournois, le décompte du temps est tenu par un assistant. De nos jours, les amateurs se contentent d’une pendule à double décompte, identique aux pendules d’échecs. Pour la cadence de jeu, le principe le plus répandu consiste à attribuer un temps global pour la partie puis à faire suivre celui-ci d’une période supplémentaire, le byo yomi, durant laquelle chaque joueur se voit attribuer un temps limité pour chacun de ses coups (faute de quoi il perd la partie). Vu sa complexité, le décompte du byo yomi moderne nécessite l’emploi de pendules électroniques ; ce matériel n’étant pas toujours disponible, des systèmes hybrides ont été développés (comme le byo yomi canadien, dans lequel le joueur doit jouer un certain nombre de coups, douze par exemple, en moins de cinq minutes). Exemples de temps alloué et de byo yomi :

    • Partie en 30 minutes, byo yomi de 30 secondes : après avoir utilisé ses 30 minutes, le joueur dispose de 30 secondes pour chaque coup supplémentaire.

 

  • Partie en 2 heures, byo yomi de 1 minute : après avoir utilisé ses 2 heures, le joueur dispose de 1 minute pour chaque coup supplémentaire.

 

Abrégé des règles du jeu

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Remarque importante : la description qui suit, bien qu’à peu près complète, risque de s’avérer insuffisante pour pouvoir vraiment jouer ; il est recommandé de consulter plutôt à cette fin l’article détaillé. Le but est de former des territoires, ensembles d’intersections vides contrôlés par le joueur. Noir commence en déposant sur la grille vide une pierre de sa couleur. Puis, à tour de rôle, les joueurs posent une nouvelle pierre sur une intersection vide du goban. Il est permis de passer son tour mais quand les deux joueurs passent consécutivement, la partie est terminée. Les pierres adjacentes de même couleur sont connectées et forment un groupe. Les intersections vides adjacentes à un groupe sont ses libertés. Si un joueur supprime la dernière liberté, il enlève (capture ou tue) la pierre ou le groupe encerclé (voir atari). Recréer une position antérieure identique est interdit (voir règle du ko). À la fin de la partie, on compte le nombre de points de chaque joueur : on compte un point par intersection libre, et un point pour chaque prisonnier (pierre prise ou morte) capturé (pour faciliter le décompte, les prisonniers sont replacés sur les intersections des territoires de l’adversaire). Le vainqueur est celui qui possède le plus de points.

Komi

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Noir, qui joue le premier, bénéficie d’un avantage systématique. Pendant des siècles, le go s’est joué sans compensation de ce déséquilibre puis l’avantage de Noir a été évalué à cinq points et demi, sur la base d’études des parties des championnats connus. Blanc s’est donc vu attribuer autant de points supplémentaires dans les parties sans pierre de handicap. C’est cette compensation qu’on appelle le komi. Depuis quelques années, la tendance est à l’augmentation du komi qui est passé à 6,5 points en Corée et au Japon et même 7,5 points en Chine ainsi qu’en France. Dans le cas des parties avec pierres de handicap, le komi est réduit à un demi-point. Le demi-point du komi rend impossible les parties nulles (appelées jigo en japonais).

Apprentissage et maîtrise du go

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En dépit de la simplicité de ses règles, le go n’est pas un jeu facile. Différentes méthodes se sont développées pour permettre aux débutants, en particulier aux enfants, de goûter les joies du go sans forcément en connaître toutes les finesses. L’une des méthodes d’initiation la mieux connue est aujourd’hui la méthode pas-à-pas qui permet au néophyte d’approcher le jeu petit à petit. Progresser au go réclame toutefois bien davantage que la simple mémorisation des règles du jeu et un bon entraînement. Le développement séculaire du jeu a en effet produit un corpus considérable de positions de référence : fuseki, joseki, tsumego, yose, etc. ainsi qu’un ensemble d’outils théoriques (tels que la notion d’influence) que le candidat à la maîtrise doit dominer s’il veut avoir la moindre chance de faire valoir ses talents parmi l’élite du go. Au Japon, le système, institutionnalisé de très longue date, est figé et sépare drastiquement « professionnels » et « amateurs » : le go professionnel est largement coopté et les candidats entrent dans les écoles de go comme insei avant de gravir éventuellement les échelons. Dans le reste du monde, le niveau de jeu est très variable selon les pays et les compétitions mais à ce jour, les joueurs occidentaux qui peuvent rivaliser sérieusement avec les champions japonais, coréens ou chinois sont rarissimes. Au Japon et en Chine, les principes stratégiques généraux ont souvent été exprimés sous la forme très accessible de proverbes. En Occident, l’accès à ces informations est compliqué par les difficultés linguistiques : la quasi totalité de la littérature technique du go est rédigée en japonais, chinois ou coréen. Les traductions que l’on commence à trouver sont un bon indice de la hausse de la popularité du go en Occident.

Kifu

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Le déroulement détaillé des parties de go est conservé sur des kifu. Les kifu sont très intéressants puisqu’ils permettent de connaître précisément la manière dont on pratiquait le go même plusieurs siècles plus tôt. Ils permettent également l’analyse post mortem des parties par les joueurs eux-mêmes. C’est ainsi que l’amateur éclairé peut apprécier aujourd’hui encore le génie d’ Honinbo Dosaku, d’ Honinbo Shusaku ou de Go Seigen, considérés comme trois des plus brillants joueurs de l’histoire du go. Assez différente de la notation algébrique utilisée aux échecs ou même de celle utilisée pour les kifu de shogi, la notation « diagramme » utilisée pour les kifu de go demande au néophyte une certaine pratique mais sa maîtrise était indispensable pour aborder les manuels de go (et beaucoup de maîtres expliquent que reproduire correctement un kifu (de partie de maitre) sur un goban fait à lui seul progresser le joueur). Cependant, pour ne pas décourager les amateurs, la pratique s’est répandue de publier les parties sous forme de nombreux diagrammes ne contenant que quelques coups ; d’autre part, la généralisation d’outils électroniques fait qu’il devient de plus en plus fréquent de voir les joueurs noter leurs parties sur des Palm Pilot, par exemple.

Classement des joueurs

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Des joueurs de go en compétition.

Le classement s’effectue différemment selon qu’il s’agit de joueurs amateurs ou de professionnels. Dans la catégorie amateur, les niveaux s’échelonnent de 30e kyu (débutant) à 1er kyu puis de 1er dan à 9e dan. Le trentième kyu étant une valeur indicative, il n’y a théoriquement pas de limite inférieure. Chez les professionnels (on en dénombre près de 400 au Japon), les classements vont de 1er à 9e dan. Un niveau de 1er dan professionnel correspond environ à un 7e dan amateur. S’appuyant sur d’anciens principes de classification chinois, le niveau de 9e dan devrait toujours correspondre au meilleur niveau existant (ou même possible : à l’époque classique, il arrivait que ce titre ne soit pas décerné), c’est pourquoi le titre de 10e dan était honorifique (et presque une plaisanterie respectueuse) avant de devenir le nom de l’une des plus importantes compétitions professionnelles de go au Japon. Entre amateurs, un niveau d’écart correspond à peu près à une pierre de handicap, ou encore à une probabilité de victoire d’environ deux parties sur trois. Entre joueurs professionnels, c’est environ trois niveaux d’écart (et peut-être même quatre) qui correspondent à une pierre de handicap. En Europe, un classement Elo commun aux joueurs amateurs et professionnels, est parfois utilisé pour effectuer un classement plus précis.

Parties à handicap

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Pour permettre à des joueurs de niveaux différents de s’affronter, le plus fort accorde un avantage au plus faible. Ce dernier, qui joue Noir, bénéficie alors de plusieurs pierres posées sur le goban avant le début de la partie. Contrairement à l’habitude, dans une partie à handicap, c’est Blanc qui commence après la pose des pierres de handicap (mais certaines règles permettent en fait à Noir d’utiliser son premier coup pour poser les pierres de handicap où il le souhaite). Par convention, les pierres d’avance accordées au joueur le plus faible sont positionnées sur les hoshi, intersections marquées par un point un peu plus épais sur le goban. Noir peut ainsi poser de deux à neuf pierres de handicap suivant le niveau relatif des deux joueurs. Si la différence de niveau n’est que d’une pierre, Noir joue le premier et Blanc renonce au komi ce qui constitue un léger avantage pour Noir. Le komi peut parfois être inversé (il va à Noir) si le niveau relatif des deux joueurs est inférieur à une pierre mais plus grand que le simple renoncement au komi.

Informatique et jeu de go

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Son apparente simplicité semble faire du go un candidat idéal à l’exploration informatique. Mais des difficultés considérables ne tardent pas à surgir. La taille du goban détermine une combinatoire qui dépasse de très loin les possibilités de calcul des ordinateurs (la taille très approximative de l’arbre des possibilités du jeu de go est environ de 10600, le nombre 361!/100! des différentes parties de plus de 260 coups). Cette difficulté est amplifiée par d’autres caractéristiques du jeu : la nature de la condition de victoire, le placement virtuellement illimité de chaque pierre, la nature non locale de la règle du ko, le haut niveau de reconnaissance de formes exigé. Pour ces raisons, certains chercheurs en intelligence artificielle considèrent le go comme un meilleur test que les échecs. Malgré leurs progrès, les logiciels de go sont aujourd’hui encore loin d’égaler les performances des programmes d’échecs. Ainsi en 1997, Janice Kim, shodan professionnelle, battait le programme HandTalk malgré un handicap de 25 pierres puis en 1998, Martin Müller, sixième dan amateur, battait Many Faces of Go malgré un handicap de 29 pierres. En 2002, le jeu sur un goban 5×5 a été résolu par le programme MIGOS (MIni GO Solver) de Erik van der Werf, fruit de la recherche de 4 472 000 000 nœuds (environ 4 heures sur un P4 2,0 GHz). Sa thèse développe plus largement la résolution du go 5×5. À partir de 2006, la programmation du jeu de go a fait des progrès importants notamment grâce à la méthode de Monte-Carlo. Les programmes parviennent désormais à égaler des joueurs de haut niveau sur un goban de taille 9×9 ou à des handicaps de 6 à 9 pierres sur un goban de taille 19×19. En 2009, les meilleurs programmes sont parvenus (en parties rapides) à obtenir un niveau de 1er dan amateur sur le serveur KGS. Comme pour la plupart des jeux, le recours à Internet se généralise et l’on recense un grand nombre de serveurs de jeu de go, certains réunissant des milliers de joueurs.

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Go (game)

From Wikipedia, the free encyclopedia
For other uses, see Go. « Goe » redirects here. For other uses, see GOE.
Go (game)
photograph of Go equipment with game in progress Go is played on a grid of black painted lines (usually 19×19). The playing pieces, called stones, are played on the intersections of the lines.
Players 2
Age range PCs: 3+; real board: 6+ [1]
Setup time Virtually none
Playing time Casual: 20–90 minutes Tournament: 1–6 hours [a]
Random chance None
Skills required Tactics, strategy, observation
1 Some professional games, especially in Japan, take more than 16 hours and are played in sessions spread over two days.
Go (game)
Chinese name
Traditional Chinese ??
Simplified Chinese ??
Transcriptions
Japanese name
Kanji ?, ??
Transcriptions
Korean name
Hangul ??
Transcriptions
Tibetan name
Tibetan
Transcriptions
This article contains Chinese, Korean and Japanese characters. Without proper rendering support, you may see question marks, boxes, or other symbols.

Go ( Japanese:? ?), known as weiqi in Chinese and baduk in Korean, is an ancient board game for two players that originated in China more than 2,000 years ago. The game is noted for being rich in strategy despite its relatively simple rules (see Rules of Go). The game is played by two players who alternately place black and white stones on the vacant intersections (called « points ») of a grid of 19×19 lines. Once placed on the board, stones cannot be moved elsewhere, unless they are surrounded and captured by the opponent’s stones. The object of the game is to secure (surround) a larger portion of the board than the opponent. When a game concludes, the controlled points (territory) are counted along with captured stones or your own stones (depending on the rule-set) and a predetermined compensation ( » komi ») to determine who has more points. Games may also be won by resignation, if for example one side has suffered a severe tactical loss (too many stones captured, etc.). Placing stones close together usually helps them support each other and avoid capture; on the other hand, placing stones far apart creates influence across more of the board. Part of the strategic difficulty of the game stems from finding a balance between such conflicting interests. Players strive to serve both defensive and offensive purposes and choose between tactical urgency and strategic plans. At its basis, the game is one of simple logic, while in advanced play the game involves complex heuristics and tactical analysis. Beginning players first learn the simple mechanics of how stones interact, while intermediate students learn concepts such as initiative (« sente »), influence, and the proper timing of moves. Go originated in ancient China sometime before the 3rd century BC (exactly when is unknown), by which time it was already a popular pastime, as indicated by a reference to the game in the Analects of Confucius. Archaeological evidence shows that the early game was played on a board with a 17×17 grid, but by the time that the game spread to Korea and Japan in about the 5th and 7th centuries respectively, the boards with a 19×19 grid had become standard. The game is most popular in East Asia. An estimate done in 2003 places the number of Go players worldwide at approximately 27 million. [2] Go reached the West through Japan, which is why it is commonly known internationally by its Japanese name. [nb 1]

Contents

 

 

 

 

 

 

 

Rules

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Main article: Rules of Go

Although there are some minor differences between rule sets used in different countries, [3] most notably in Chinese and Japanese scoring rules, [4] these differences do not seriously affect the tactics and strategy of the game. Except where noted otherwise, the basic rules presented here are valid independent of the scoring rules used. The scoring rules are explained separately. Go concepts for which there is no ready English equivalent are commonly called by their Japanese names.

Basic rules

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One black chain and two white chains, their liberties shown with dots. Note that liberties are shared among all stones of a chain.

Two players, Black and White, take turns placing a stone (game piece) of their own color on a vacant point (intersection) of the grid on a Go board. Black moves first. If there is a large difference in skill between the players, Black is sometimes allowed to place two or more stones on the board for their first move – see Go handicaps for details. The official grid comprises 19×19 lines, though the rules can be applied to any grid size; 13×13 and 9×9 are popular choices to teach beginners. [5] Once placed, a stone may not be moved to a different point. [6] Vertically and horizontally adjacent stones of the same color form a chain (also called a string) that shares its liberties (see below) in common, cannot subsequently be subdivided, and in effect becomes a single larger stone. [7] Only stones connected to one another by the lines on the board create a chain; stones that are diagonally adjacent are not connected. Chains may be expanded by placing additional stones on adjacent intersections, and can be connected together by placing a stone on an intersection that is adjacent to two or more chains of the same color.

If white plays at A, the black chain loses its last liberty. It is captured and removed from the board.

A vacant point adjacent to a stone is called a liberty for that stone. [8] [nb 2] Stones in a chain share their liberties. A chain of stones must have at least one liberty to remain on the board. When a chain is surrounded by opposing stones so that it has no liberties, it is captured and removed from the board. Most rule sets, except the Chinese rules, do not allow a player to place a stone in such a way that one of their own chains is left without liberties, subject to the following important exception. [9] The rule does not apply if playing the new stone results in the capture of one or more of the opponent’s stones. In this case, the opponent’s stones are captured first, leaving the newly played stone at least one liberty. [10] The rule just stated is said to prohibit suicide. (Since suicide is very rarely useful, making it legal does not significantly alter the nature of the game.)

Go ul.svg Go u.svg Go u.svg Go u.svg Go ur.svg
Go l.svg Go b.svg Go w.svg Go .svg Go r.svg
Go b.svg Go c.svg Go b1.svg Go w.svg Go r.svg
Go l.svg Go b.svg Go w.svg Go .svg Go r.svg
Go dl.svg Go d.svg Go d.svg Go d.svg Go dr.svg
An example of a situation in which the ko rule applies

Players are not allowed to make a move that returns the game to a previous position. This rule, called the ko rule (from the Japanese ? ko « eon »), prevents unending repetition. [11] See the example to the right: Black has just played the stone marked 1, capturing a white stone at the intersection marked with a circle. If White were now allowed to play on the marked intersection, that move would capture the black stone marked 1 and recreate the situation before Black made the move marked 1. Allowing this could result in an unending cycle of captures by both players. The ko rule therefore prohibits White from playing at the marked intersection immediately. Instead White must play elsewhere; Black can then end the ko by filling at the marked intersection, creating a five-stone Black chain. If White wants to continue the ko (that specific repeating position), White will try to find a play elsewhere on the board that Black must answer; if Black answers, then White can retake the ko. A repetition of such exchanges is called a ko fight. [12] While the various rule sets agree on the ko rule prohibiting returning the board to an immediately previous position, they deal in different ways with the relatively uncommon situation in which a player might recreate a past position that is further removed. See Rules of Go: Repetition for further information. Instead of placing a stone, a player may pass. This usually occurs when they believe no useful moves remain. When both players pass consecutively, the game ends and is then scored.

Scoring rules

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There are two basic scoring systems used to determine the winner at the end of a game; they almost always give the same result. Territory scoring counts the number of empty points your stones surround, together with the number of stones you captured. While it originated in China, today it is commonly associated with Japan and Korea. Area scoring counts the number of points your stones occupy and surround. It is associated with contemporary Chinese play and was probably established there during the Ming Dynasty in the 15th or 16th century. [13]

Detailed description

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After both players have passed consecutively, the stones that are still on the board but unable to avoid capture, called dead stones, are removed. (When both sides have passed, skilled players will nearly always agree which stones are dead and which are alive.) Area scoring (including Chinese): A player’s score is the number of stones they have on the board, plus the number of empty intersections surrounded by that player’s stones. Territory scoring (including Japanese and Korean): In the course of the game, each player retains the stones they capture, termed prisoners. Any dead stones removed at the end of the game become prisoners. The score is the number of empty points enclosed by a player’s stones, plus the number of prisoners captured by that player. [nb 3] If there is disagreement about which stones are dead, then under area scoring rules, the players simply resume play to resolve the matter. The score is computed using the position after the next time the players pass consecutively. Under territory scoring, the rules are considerably more complex; however, in practice, players will generally play on, and, once the status of each stone has been determined, return to the position at the time the first two consecutive passes occurred and remove the dead stones. For further information, see Rules of Go. Given that the number of stones a player has on the board is related to the number of prisoners the opponent has taken, the resulting net score (the difference between Black and White’s respective scores) under both rulesets is often identical and rarely differs by more than a point. [14]

Life and death

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See also: Life and death

While not actually mentioned in the rules of Go (at least in simpler rule sets, such as those of New Zealand and the US), the concept of a living group of stones is necessary for a practical understanding of the game. [15]

Go ulc.svg Go b.svg Go b.svg Go w.svg Go u.svg Go w.svg Go b.svg Go uc.svg Go b.svg
Go b.svg Go c.svg Go b.svg Go w.svg Go .svg Go w.svg Go b.svg Go b.svg Go rc.svg
Go b.svg Go b.svg Go w.svg Go w.svg Go .svg Go w.svg Go w.svg Go b.svg Go b.svg
Go w.svg Go w.svg Go w.svg Go .svg Go .svg Go .svg Go w.svg Go b.svg Go rc.svg
Go l.svg Go .svg Go .svg Go .svg Go .svg Go .svg Go w.svg Go b.svg Go b.svg
Go w.svg Go w.svg Go .svg Go .svg Go .svg Go .svg Go w.svg Go w.svg Go w.svg
Go b.svg Go w.svg Go w.svg Go w.svg Go w.svg Go .svg Go w.svg Go b.svg Go b.svg
Go l.svg Go b.svg Go b.svg Go b.svg Go w.svg Go .svg Go w.svg Go b.svg Go rc.svg
Go b.svg Go b.svg Go dc.svg Go b.svg Go w.svg Go d.svg Go w.svg Go b.svg Go b.svg
Examples of eyes

When a group of stones is mostly surrounded and has no options to connect with friendly stones elsewhere, the status of the group is either alive, dead or unsettled. A group of stones is said to be alive if it cannot be captured, even if the opponent is allowed to move first. Conversely, a group of stones is said to be dead if it cannot avoid capture, even if the owner of the group is allowed the first move. Otherwise, the group is said to be unsettled: in such a situation, the player that moves first may be able to either make it alive if he is the owner, or kill it if he is the group owner’s opponent. [15]

Go ul.svg Go b.svg Go b.svg Go w.svg Go u.svg Go w.svg Go u.svg Go u.svg Go ur.svg
Go b.svg Go .svg Go b.svg Go w.svg Go w.svg Go w.svg Go w.svg Go w.svg Go w.svg
Go b.svg Go b.svg Go w.svg Go w.svg Go b.svg Go b.svg Go b.svg Go b.svg Go b.svg
Go w.svg Go w.svg Go w.svg Go b.svg Go b.svg Go .svg Go b.svg Go .svg Go b.svg
Go b.svg Go b.svg Go b.svg Go w.svg Go .svg Go b.svg Go b.svg Go b.svg Go b.svg
Go lc.svg Go c.svg Go b.svg Go w.svg Go w.svg Go w.svg Go w.svg Go w.svg Go b.svg
Go w.svg Go w.svg Go w.svg Go b.svg Go w.svg Go .svg Go w.svg Go b.svg Go b.svg
Go b.svg Go b.svg Go b.svg Go b.svg Go w.svg Go w.svg Go w.svg Go b.svg Go r.svg
Go dl.svg Go b.svg Go d.svg Go b.svg Go w.svg Go d.svg Go w.svg Go b.svg Go b.svg
Example of seki (mutual life)

For a group to be alive, it needs to be able to create at least two  » eyes » if threatened. An eye is an empty point that is surrounded by friendly stones and where the opponent can never play due to the suicide rule. If two such eyes exist, the opponent can never capture a group of stones, because it will always have at least two liberties. One eye is not enough for life, because a point that would normally be suicide may be played upon if doing so fills the last liberty of opposing stones, thereby capturing those stones. In the « Examples of eyes » diagram, all the circled points are eyes. The two black groups in the upper corners are alive, as both have at least two eyes. The groups in the lower corners are dead, as both have only one eye. The group in the lower left may seem to have two eyes, but the surrounded empty point without a circle is not actually an eye. White can play there and take a black stone. Such a point is often called a false eye. [15] There is a rare exception to the requirement that a group must have two eyes to be alive, a situation called seki (or mutual life). Where different coloured groups are adjacent and share liberties, the situation may reach a position when neither player wants to move first, because doing so would allow the opponent to capture; such situations therefore remain on the board. [nb 4] Sekis can occur in many ways. The simplest are: (1) each player has a group without eyes and they share two liberties, and (2) each player has a group with one eye and they share one more liberty. In the « Example of seki (mutual life) » diagram, the circled points are liberties shared by both a black and a white group. Neither player wants to play on a circled point, because doing so would allow the opponent to capture. All the other groups in this example, both black and white, are alive with at least two eyes. Sekis are unusual, but can result from an attempt by one player to invade and kill a nearly settled group of the other player. [15]

History

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Main article: History of Go

Origin in China

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Woman Playing Go (Tang Dynasty ca. 744) Discovered at the Astana Graves.

The earliest written reference to the game is generally recognized as the historical annal Zuo Zhuan [16] (c. 4th century BC), [17] referring to a historical event of 548 BC. It is also mentioned in Book XVII of the Analects of Confucius (c. 3rd century BC) [17] and in two books written by Mencius [18] (c. 3rd century BC). [17] In all of these works, the game is referred to as (?). Today, in China, it is known as weiqi ( simplified Chinese: ??; traditional Chinese: ??; pinyin: wéiqí; Wade–Giles: wei ch’i), literally the « encirclement board game ». Go was originally played on a 17×17 line grid, but a 19×19 grid became standard by the time of the Tang Dynasty (618–907). [19] Legends trace the origin of the game to Chinese emperor Yao (2337–2258 BC), said to have had his counselor Shun design it for his unruly son, Danzhu to favorably influence him. [20] Other theories suggest that the game was derived from Chinese tribal warlords and generals, who used pieces of stone to map out attacking positions. [21] In China, Go was perceived as the popular game of the aristocracy, while Xiangqi (Chinese chess) was the game of the masses. Go was considered one of the four cultivated arts of the Chinese scholar gentleman, along with calligraphy, painting and playing the musical instrument guqin. [22]

Spread to Korea and Japan

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Weiqi was introduced to Korea sometime between the 5th and 7th centuries AD, and was popular among the higher classes. In Korea, the game is called baduk ( hangul: ??), and a variant of the game called Sunjang baduk was developed by the 16th century. Sunjang baduk became the main variant played in Korea until the end of the 19th century. [23] [24]

Korean players, in traditional dress, play in a photograph dated between 1910 and 1920.

The game reached Japan in the 7th century AD —where it is called go (? ?) or igo (?? ?)—the game became popular at the Japanese imperial court in the 8th century, [25] and among the general public by the 13th century. [26] In 1603, Tokugawa Ieyasu re-established Japan’s unified national government. In the same year, he assigned the then-best player in Japan, a Buddhist monk named Nikkai (né Kano Yosaburo, 1559), to the post of Godokoro (Minister of Go). [27] Nikkai took the name Honinbo Sansa and founded the Honinbo Go school. [27] Several competing schools were founded soon after. [27] These officially recognized and subsidized Go schools greatly developed the level of play and introduced the dan/kyu style system of ranking players. [28] Players from the four schools (Honinbo, Yasui, Inoue and Hayashi) competed in the annual castle games, played in the presence of the shogun. [29]

Go in the West

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Despite its widespread popularity in East Asia, Go has been slow to spread to the rest of the world. Although there are some mentions of the game in western literature from the 16th century forward, Go did not start to become popular in the West until the end of the 19th century, when German scientist Oskar Korschelt wrote a treatise on the game. [30] By the early 20th century, Go had spread throughout the German and Austro-Hungarian empires. In 1905, Edward Lasker learned the game while in Berlin. When he moved to New York, Lasker founded the New York Go Club together with (amongst others) Arthur Smith, who had learned of the game while touring the East and had published the book The Game of Go in 1908. [31] Lasker’s book Go and Go-moku (1934) helped spread the game throughout the US, [31] and in 1935, the American Go Association was formed.(In the American Go Association, when passing, you must give the opposing player a stone as a capture). Two years later, in 1937, the German Go Association was founded. World War II put a stop to most Go activity, but after the war, Go continued to spread. [32] For most of the 20th century, the Japan Go Association played a leading role in spreading Go outside East Asia by publishing the English-language magazine Go Review in the 1960s; establishing Go centers in the US, Europe and South America; and often sending professional teachers on tour to Western nations. [33] In 1996, NASA astronaut Daniel Barry and Japanese astronaut Koichi Wakata became the first people to play Go in space. Both astronauts were awarded honorary dan ranks by the Nihon Ki-in. [34] As of 2008, the International Go Federation has a total of 71 member countries. [35] It has been claimed that across the world 1 person in every 222 plays Go. [36]

Equipment

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Main article: Go equipment

A traditional Japanese set, with floor board (?? goban), bowls (?? goke) and stones (?? goishi)

It is possible to play Go with a simple paper board and coins or plastic tokens for the stones. More popular midrange equipment includes cardstock, a laminated particle board, or wood boards with stones of plastic or glass. More expensive traditional materials are still used by many players. The most expensive Go sets have black stones carved from slate and white stones carved from translucent white shells.

Traditional equipment

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Boards

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The Go board (generally referred to by its Japanese name goban) typically measures between 45 and 48 cm (18 and 19 in) in length (from one player’s side to the other) and 42 to 44 cm (17 to 17 in) in width. Chinese boards are slightly larger, as a traditional Chinese Go stone is slightly larger to match. The board is not square; there is a 15:14 ratio in length to width, because with a perfectly square board, from the player’s viewing angle the perspective creates a foreshortening of the board. The added length compensates for this. [37] There are two main types of boards: a table board similar in most respects to other game boards like that used for chess, and a floor board, which is its own free-standing table and at which the players sit. The traditional Japanese goban is between 10 and 18 cm (3.9 and 7.1 in) thick and has legs; it sits on the floor (see picture to right). [37] It is preferably made from the rare golden-tinged Kaya tree (Torreya nucifera), with the very best made from Kaya trees up to 700 years old. More recently, the related California Torreya (Torreya californica) has been prized for its light color and pale rings, as well as its less expensive and more readily available stock. The natural resources of Japan have been unable to keep up with the enormous demand for the slow-growing Kaya trees; both T. nucifera and T. californica take many hundreds of years to grow to the necessary size, and they are now extremely rare, raising the price of such equipment tremendously. [38] As Kaya trees are a protected species in Japan, they cannot be harvested until they have died. Thus, an old-growth, floor-standing Kaya goban can easily cost in excess of US$10,000 with the highest-quality examples costing more than $60,000. [39] Other, less expensive woods often used to make quality table boards in both Chinese and Japanese dimensions include Hiba (Thujopsis dolabrata), Katsura (Cercidiphyllum japonicum), Kauri (Agathis), and Shin Kaya (various varieties of spruce, commonly from Alaska, Siberia and China’s Yunnan Province). [38] So-called Shin Kaya is a potentially confusing merchant’s term: shin means « new », and thus shin kaya is best translated « faux kaya », because the woods so described are biologically unrelated to Kaya. [38]

Stones

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A full set of Go stones (goishi) usually contains 181 black stones and 180 white ones; a 19×19 grid has 361 points, so there are enough stones to cover the board, and Black gets the extra odd stone because that player goes first. Traditional Japanese stones are double-convex, and made of clamshell (white) and slate (black). [40] The classic slate is nachiguro stone mined in Wakayama Prefecture and the clamshell from the Hamaguri clam; however, due to a scarcity in the Japanese supply of this clam, the stones are most often made of shells harvested from Mexico. [40] Historically, the most prized stones were made of jade, often given to the reigning emperor as a gift. [40] In China, the game is traditionally played with single-convex stones [40] made of a composite called Yunzi. The material comes from Yunnan Province and is made by sintering a proprietary and trade-secret mixture of mineral compounds. This process dates to the Tang Dynasty and, after the knowledge was lost in the 1920s during the Chinese Civil War, was rediscovered in the 1960s by the now state-run Yunzi company. The material is praised for its colors, its pleasing sound as compared to glass or to synthetics such as melamine, and its lower cost as opposed to other materials such as slate/shell. The term « yunzi » can also refer to a single-convex stone made of any material; however, most English-language Go suppliers will specify Yunzi as a material and single-convex as a shape to avoid confusion, as stones made of Yunzi are also available in double-convex while synthetic stones can be either shape. Traditional stones are made so that black stones are slightly larger in diameter than white; this is to compensate for the optical illusion created by contrasting colors that would make equal-sized white stones appear larger on the board than black stones. [40] [nb 5]

An example of single-convex stones and Go Seigen bowls. These particular stones are made of Yunzi material, and the bowls of jujube wood.

Bowls

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The bowls for the stones are shaped like a flattened sphere with a level underside. [41] The lid is loose fitting and upturned before play to receive stones captured during the game. Chinese bowls are slightly larger, and a little more rounded, a style known generally as Go Seigen; Japanese Kitani bowls tend to have a shape closer to that of the bowl of a snifter glass, such as for brandy. The bowls are usually made of turned wood. Rosewood is the traditional material for Japanese bowls, but is very expensive; wood from the Chinese jujube date tree, which has a lighter color (it is often stained) and slightly more visible grain pattern, is a common substitute for rosewood, and traditional for Go Seigen-style bowls. Other traditional materials used for making Chinese bowls include lacquered wood, ceramics, stone and woven straw or rattan. The names of the bowl shapes, Go Seigen and Kitani, pay homage to two 20th-century professional Go players by the same names, of Chinese and Japanese nationality, respectively, who are referred to as the « Fathers of modern Go ». [42]

Modern and low-cost alternatives

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In clubs and at tournaments, where large numbers of sets must be purchased and maintained by one organization, expensive traditional sets are not usually used. For these situations, table boards are usually used instead of floor boards, and are either made of a lower-cost wood such as spruce or bamboo, or are flexible mats made of vinyl that can be rolled up. In such cases, the stones are usually made of glass, plastic or resin (such as melamine or Bakelite) rather than slate and shell. Bowls are often made of plastic or inexpensive wood. Common « novice » Go sets are all-inclusive kits made of particle board or plywood, with plastic or glass stones, that either fold up to enclose the stone containers or have pull-out drawers to keep stones. In relative terms, these sets are inexpensive, costing US$20–$40 depending on component quality, and thus are popular with casual Go players. Magnetic sets are also available, either as portable travel sets or in larger sizes for educational purposes.

Playing technique and etiquette

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A pair of Shanghainese men demonstrate the traditional technique of holding a stone.

The traditional way to place a Go stone is to first take one from the bowl, gripping it between the index and middle fingers, with the middle finger on top, and then placing it directly on the desired intersection. [43] It is considered respectful towards one’s opponent to place one’s first stone in the upper right-hand corner. [44] It is permissible to emphasize select moves by striking the board more firmly than normal, thus producing a sharp clack.

Time control

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See also: Time control and Byoyomi

A game of Go may be timed using a game clock. Formal time controls were introduced into the professional game during the 1920s and were controversial. [45] Adjournments and sealed moves began to be regulated in the 1930s. Go tournaments use a number of different time control systems. All common systems envisage a single main period of time for each player for the game, but they vary on the protocols for continuation (in overtime) after a player has finished that time allowance. [nb 6] The most widely used time control system is the so called byoyomi [nb 7] system. The top professional Go matches have timekeepers so that the players do not have to press their own clocks. Two widely used variants of the byoyomi system are: [46]

    • Standard byoyomi: After the main time is depleted, a player has a certain number of time periods (typically around thirty seconds). After each move, the number of full time periods that the player took (possibly zero) is subtracted. For example, if a player has three thirty-second time periods and takes thirty or more (but less than sixty) seconds to make a move, they lose one time period. With 60–89 seconds, they lose two time periods, and so on. If, however, they take less than thirty seconds, the timer simply resets without subtracting any periods. Using up the last period means that the player has lost on time.

 

  • Canadian byoyomi: After using all of their main time, a player must make a certain number of moves within a certain period of time, such as twenty moves within five minutes. [46] [nb 8] If the time period expires without the required number of stones having been played, then the player has lost on time. [nb 9]

 

 

Notation and recording games

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See also: Kifu

Go games are recorded with a simple coordinate system. This is comparable to algebraic chess notation, except that Go stones do not move and thus require only one coordinate per turn. Coordinate systems include purely numerical (4-4 point), hybrid (K3), and purely alphabetical. [47] The Smart Game Format uses alphabetical coordinates internally, but most editors represent the board with hybrid coordinates as this reduces confusion. The Japanese word kifu is sometimes used to refer to a game record.

Competitive play

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Ranks and ratings

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Main article: Go ranks and ratings

Three Japanese professional Go players observe some younger amateurs as they dissect a life and death problem in the corner of the board, at the US Go Congress in Houston, Texas, 2003.

In Go, rank indicates a player’s skill in the game. Traditionally, ranks are measured using kyu and dan grades, [48] a system which also has been adopted by many martial arts. More recently, mathematical rating systems similar to the Elo rating system have been introduced. [49] Such rating systems often provide a mechanism for converting a rating to a kyu or dan grade. [49] Kyu grades (abbreviated k) are considered student grades and decrease as playing level increases, meaning 1st kyu is the strongest available kyu grade. Dan grades (abbreviated d) are considered master grades, and increase from 1st dan to 7th dan. First dan equals a black belt in eastern martial arts using this system. The difference among each amateur rank is one handicap stone. For example, if a 5k plays a game with a 1k, the 5k would need a handicap of four stones to even the odds. Top-level amateur players sometimes defeat professionals in tournament play. [50] Professional players have professional dan ranks (abbreviated p), these ranks are separate from amateur ranks The rank system comprises, from the lowest to highest ranks:

Rank Type Range Stage
Double-digit kyu 30–20k Beginner
Double-digit kyu 19–10k Casual player
Single-digit kyu 9–1k Intermediate/club player
Amateur dan 1–7d (where 8d is special title) Expert player
Professional dan 1–9p (where 10p is special title) Professionals

Tournament and match rules

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See also: Go competitions

Tournament and match rules deal with factors that may influence the game but are not part of the actual rules of play. Such rules may differ between events. Rules that influence the game include: the setting of compensation points ( komi), handicap strategies, and time control parameters. Rules that do not generally influence the game are: the tournament system, pairing strategies, and placement criteria. Common tournament systems used in Go include the McMahon system, [51] Swiss system, league systems and the knockout system. Tournaments may combine multiple systems; many professional Go tournaments use a combination of the league and knockout systems. [52] Tournament rules may also set the following:

    • compensation points, called komi, which compensate the second player for the first move advantage of his opponent; tournaments commonly use a compensation in the range of 5–8 points, [53] generally including a half-point to prevent draws;

 

  • compensation stones placed on the board before alternate play, allowing players of different strengths to play competitively (see Go handicap for more information); and

 

 

  • superko: Although the basic ko rule described above covers more than 95% of all cycles occurring in games, [54] there are some complex situations— triple ko, eternal life, [nb 10] etc.—that are not covered by it but would allow the game to cycle indefinitely. To prevent this, the ko rule is sometimes extended to disallow the repetition of any previous position. This extension is called superko. [54]

 

 

Top players

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See also: Go players and Go professional

Although the game was developed in China, the establishment of the Four Go houses by Tokugawa Ieyasu at the start of the 17th century shifted the focus of the Go world to Japan. State sponsorship, allowing players to dedicate themselves full time to study of the game, and fierce competition between individual houses resulted in a significant increase in the level of play. During this period, the best player of his generation was given the prestigious title Meijin (master) and the post of Godokoro (minister of Go). Of special note are the players who were dubbed Kisei (Go Sage). The only three players to receive this honor were Dosaku, Jowa and Shusaku, all of the house Honinbo. [42]

Honinbo Shusai (left), last head of house Honinbo, plays against then-up-and-coming Go Seigen in the game of the century.

After the end of the Tokugawa shogunate and the Meiji Restoration period, the Go houses slowly disappeared, and in 1924, the Nihon Ki-in (Japanese Go Association) was formed. Top players from this period often played newspaper-sponsored matches of 2–10 games. [55] Of special note are Go Seigen (Chinese: Wu Qingyuan), who scored an impressive 80% in these matches, [56] and Minoru Kitani, who dominated matches in the early 1930s. [57] These two players are also recognized for their groundbreaking work on new opening theory ( Shinfuseki). [58] For much of the 20th century, Go continued to be dominated by players trained in Japan. Notable names included Eio Sakata, Rin Kaiho (born in China), Masao Kato, Koichi Kobayashi and Cho Chikun (born Cho Ch’i-hun, South Korea). [59] Top Chinese and Korean talents often moved to Japan, because the level of play there was high and funding was more lavish. One of the first Korean players to do so was Cho Namchul, who studied in the Kitani Dojo 1937–1944. After his return to Korea, the Hanguk Kiwon (Korea Baduk Association) was formed and caused the level of play in South Korea to rise significantly in the second half of the 20th century. [60] In China, the game declined during the Cultural Revolution (1966–1976) but quickly recovered in the last quarter of the 20th century, bringing Chinese players, such as Nie Weiping and Ma Xiaochun, on par with their Japanese and Korean counterparts. [61]

Korean player Lee Chang-ho, considered by many to be the best player of the late 20th and early 21st centuries, plays against Russian player Alexandre Dinerchtein, seven-time European Champion and one of the few Western players to reach professional status.

With the advent of major international titles from 1989 onward, it became possible to compare the level of players from different countries more accurately. Korean players such as Lee Chang-ho, Cho Hunhyun, Lee Sedol and Yoo Changhyuk dominated international Go and won an impressive number of titles. [62] Several Chinese players also rose to the top in international Go, most notably Ma Xiaochun, Chang Hao and Gu Li. As of 2008, Japan lags behind in the international Go scene. Historically, as with most sports and games, more men than women have played Go. Special tournaments for women exist, but until recently, men and women did not compete together at the highest levels; however, the creation of new, open tournaments and the rise of strong female players, most notably Rui Naiwei, have in recent years highlighted the strength and competitiveness of emerging female players. [63] The level in other countries has traditionally been much lower, except for some players who had preparatory professional training in Asia. [nb 11] Knowledge of the game has been scant elsewhere up until the 20th century. A famous player of the 1920s was Edward Lasker. [nb 12] It was not until the 1950s that more than a few Western players took up the game as other than a passing interest. In 1978, Manfred Wimmer became the first Westerner to receive a professional player’s certificate from an Asian professional Go association. [64] In 2000, a Westerner, Michael Redmond, finally achieved the top rank awarded by an Asian Go association, 9 dan. In total, as of 2008, only nine non-Asian Go players have ever achieved professional status in Asian associations.

Tactics

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Main article: Go strategy and tactics

In Go, tactics deal with immediate fighting between stones, capturing and saving stones, life, death and other issues localized to a specific part of the board. Larger issues, not limited to only part of the board, are referred to as strategy, and are covered in their own section.

Capturing tactics

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There are several tactical constructs aimed at capturing stones. [65] These are among the first things a player learns after understanding the rules. Recognizing the possibility that stones can be captured using these techniques is an important step forward.

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Go ul.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg
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A ladder. Black cannot escape unless the ladder connects to friendly stones further down the board.

The most basic technique is the ladder. [66] To capture stones in a ladder, a player uses a constant series of capture threats—called atari—to force the opponent into a zigzag pattern as shown in the diagram to the right. Unless the pattern runs into friendly stones along the way, the stones in the ladder cannot avoid capture. Experienced players will recognize the futility of continuing the pattern and will play elsewhere. The presence of a ladder on the board does give a player the option to play a stone in the path of the ladder, thereby threatening to rescue their stones, forcing a response. Such a move is called a ladder breaker and may be a powerful strategic move. In the diagram, Black has the option of playing a ladder breaker.

Go ul.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg
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A net. The chain of three black stones cannot escape in any direction.

Another technique to capture stones is the so-called net, [67] also known by its Japanese name, geta. This refers to a move that loosely surrounds some stones, preventing their escape in all directions. An example is given in the diagram to the left. It is generally better to capture stones in a net than in a ladder, because a net does not depend on the condition that there are no opposing stones in the way, nor does it allow the opponent to play a strategic ladder breaker.

Go ul.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg
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Go l.svg Go .svg Go .svg Go w.svg Go b.svg Go .svg Go .svg Go .svg Go .svg
Go l.svg Go .svg Go .svg Go .svg Go b.svg Go .svg Go .svg Go .svg Go .svg
A snapback. Although Black can capture the white stone by playing at the circled point, White can then snap back by playing at 1 again.

A third technique to capture stones is the snapback. [68] In a snapback, one player allows a single stone to be captured, then immediately plays on the point formerly occupied by that stone; by so doing, the player captures a larger group of their opponent’s stones, in effect snapping back at those stones. An example can be seen on the right. As with the ladder, an experienced player will not play out such a sequence, recognizing the futility of capturing only to be captured back immediately.

Reading ahead

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One of the most important skills required for strong tactical play is the ability to read ahead. Reading ahead includes considering available moves to play, the possible responses to each move, and the subsequent possibilities after each of those responses. Some of the strongest players of the game can read up to 40 moves ahead even in complicated positions. [69] As explained in the scoring rules, some stone formations can never be captured and are said to be alive, while other stones may be in the position where they cannot avoid being captured and are said to be dead. Much of the practice material available to students of the game comes in the form of life and death problems, also known as tsumego. [70] In such problems, players are challenged to find the vital move sequence that will kill a group of the opponent or save a group of their own. Tsumego are considered an excellent way to train a player’s ability at reading ahead, [70] and are available for all skill levels, some posing a challenge even to top players.

Ko fighting

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In situations when the Ko rule applies, a ko fight may occur. [12] If the player who is prohibited from capture is of the opinion that the capture is important, because it prevents a large group of stones from being captured for instance, the player may play a ko threat. [12] This is a move elsewhere on the board that threatens to make a large profit if the opponent does not respond. If the opponent does respond to the ko threat, the situation on the board has changed, and the prohibition on capturing the ko no longer applies. Thus the player who made the ko threat may now recapture the ko. Their opponent is then in the same situation and can either play a ko threat as well, or concede the ko by simply playing elsewhere. If a player concedes the ko, either because they do not think it important or because there are no moves left that could function as a ko threat, they have lost the ko, and their opponent may connect the ko. Instead of responding to a ko threat, a player may also choose to ignore the threat and connect the ko. [12] They thereby win the ko, but at a cost. The choice of when to respond to a threat and when to ignore it is a subtle one, which requires a player to consider many factors, including how much is gained by connecting, how much is lost by not responding, how many possible ko threats both players have remaining, what the optimal order of playing them is, and what the size—points lost or gained—of each of the remaining threats is. Frequently, the winner of the ko fight does not connect the ko but instead captures one of the chains that constituted their opponent’s side of the ko. [12] In some cases, this leads to another ko fight at a neighboring location.

Strategy

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Main article: Go strategy and tactics
Go ul.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go u.svg Go ur.svg
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Game 1 of the 2002 Korean LG Cup final between Choe Myeong-hun (White) and Lee Sedol (Black) [71] at the end of the opening stage; White has developed a great deal of potential territory, while Black has emphasized central influence.

Strategy deals with global influence, interaction between distant stones, keeping the whole board in mind during local fights, and other issues that involve the overall game. It is therefore possible to allow a tactical loss when it confers a strategic advantage. Go is not easy to play well. With each new level (rank) comes a deeper appreciation for the subtlety and nuances involved and for the insight of stronger players. The acquisition of major concepts of the game comes slowly. Novices often start by randomly placing stones on the board, as if it were a game of chance; they inevitably lose to experienced players who know how to create effective formations. An understanding of how stones connect for greater power develops, and then a few basic common opening sequences may be understood. Learning the ways of life and death helps in a fundamental way to develop one’s strategic understanding of weak groups. [nb 13] It is necessary to play thousands of games before one can get close to one’s ultimate potential skill level in Go. A player who both plays aggressively and can handle adversity is said to display kiai, or fighting spirit, in the game. Familiarity with the board shows first the tactical importance of the edges, and then the efficiency of developing in the corners first, then sides, then center. The more advanced beginner understands that territory and influence are somewhat interchangeable—but there needs to be a balance. This intricate struggle of power and control makes the game highly dynamic.

Basic concepts

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Main article: Go terms

Basic strategic aspects include the following:

    • Connection: Keeping one’s own stones connected means that fewer groups need defense.

 

  • Cut: Keeping opposing stones disconnected means that the opponent needs to defend more groups.

 

 

  • Life: This is the ability of stones to permanently avoid capture. The simplest and usual way is for the group to surround two eyes (separate empty areas), so that filling one eye will not kill the group; as a result, any such move is suicidal and the group cannot be captured. The fundamental strategy of Go is to create groups with life while preventing one’s opponent from doing the same.

 

 

  • Mutual life (seki): A situation in which neither player can play to a particular point without then allowing the other player to play at another point to capture. The most common example is that of adjacent groups that share their last few liberties. If either player plays in the shared liberties, they reduce their own group to a single liberty (putting themselves in atari), allowing their opponent to capture it on the next move.

 

 

  • Death: The absence of life coupled with the inability to create it, resulting in the eventual removal of a group.

 

 

  • Invasion: Setting up a new living position inside an area where the opponent has greater influence, as a means of balancing territory.

 

 

  • Reduction: Placing a stone far enough into the opponent’s area of influence to reduce the amount of territory they will eventually get, but not so far in that it can be cut off from friendly stones outside.

 

 

  • Sente: A play that forces one’s opponent to respond ( gote), such as placing an opponent’s group in atari (immediate danger of capture). A player who can regularly play sente has the initiative, as in chess, and can control the flow of the game.

 

 

  • Sacrifice: Allowing a group to die in order to carry out a play, or plan, in a more important area.

 

 

The strategy involved can become very abstract and complex. High-level players spend years improving their understanding of strategy, and a novice may play many hundreds of games against opponents before being able to win regularly.

Opening strategy

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In the opening of the game, players will usually play in the corners of the board first, as the presence of two edges make it easier for them to surround territory and establish their stones. [72] After the corners, focus moves to the sides, where there is still one edge to support a player’s stones. Opening moves are generally on the third and fourth line from the edge, with occasional moves on the second and fifth lines. In general, stones on the third line offer stability and are good defensive moves, whereas stones on the fourth line influence more of the board and are good attacking moves. In the opening, players often play established sequences called joseki, which are locally balanced exchanges; [73] however, the joseki chosen should also produce a satisfactory result on a global scale. It is generally advisable to keep a balance between territory and influence. Which of these gets precedence is often a matter of individual taste.

Phases of the game

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While the opening moves in a game have a distinct set of aims, they usually make up only 10% to at most 20% of the game. In other words, in a game of 250 moves, there may be around 30 or so opening moves, with limited « fighting ». At the end of such a game, there will also be perhaps 100 moves that are counted as « endgame », in which territories are finished off definitively and all issues on capturing stones become clear. The middle phase of the game is the most combative, and usually lasts for more than 100 moves. During the middlegame, or just « the fighting », the players invade each others’ frameworks, and attack weak groups, formations that lack the necessary two eyes for viability. Such groups must run away, i.e. expand to avoid enclosure, giving a dynamic feeling to the struggle. It is quite possible that one player will succeed in capturing a large weak group of the opponent’s, which will often prove decisive and end the game by a resignation. But matters may be more complex yet, with major trade-offs, apparently dead groups reviving, and skillful play to attack in such a way as to construct territories rather than to kill. The end of the middlegame and transition to the endgame is marked by a few features. The game breaks up into areas that do not affect each other (with a caveat about ko fights), where before the central area of the board related to all parts of it. No large weak groups are still in serious danger. Moves can reasonably be attributed some definite value, such as 20 points or fewer, rather than simply being necessary to compete. Both players set limited objectives in their plans, in making or destroying territory, capturing or saving stones. These changing aspects of the game usually occur at much the same time, for strong players. In brief, the middlegame switches into the endgame when the concepts of strategy and influence need reassessment in terms of concrete final results on the board.

Computers and Go

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Nature of the game

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See also: Go and mathematics

Computers generally model the game as a tree of moves with values assigned to them.

In combinatorial game theory terms, Go is a zero sum, perfect-information, partisan, deterministic strategy game, putting it in the same class as chess, checkers (draughts) and Reversi (Othello); however it differs from these in its game play. Although the rules are simple, the practical strategy is extremely complex. The game emphasizes the importance of balance on multiple levels and has internal tensions. To secure an area of the board, it is good to play moves close together; however, to cover the largest area, one needs to spread out, perhaps leaving weaknesses that can be exploited. Playing too low (close to the edge) secures insufficient territory and influence, yet playing too high (far from the edge) allows the opponent to invade. It has been claimed that Go is the most complex game in the world due to its vast number of variations in individual games. [74] Its large board and lack of restrictions allow great scope in strategy and expression of players’ individuality. Decisions in one part of the board may be influenced by an apparently unrelated situation in a distant part of the board. Plays made early in the game can shape the nature of conflict a hundred moves later. The game complexity of Go is such that describing even elementary strategy fills many introductory books. In fact, numerical estimates show that the number of possible games of Go far exceeds the number of atoms in the known universe. [nb 14]

Software players

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Main article: Computer Go

Go poses a daunting challenge to computer programmers. [75] While the strongest computer chess programs can defeat the best human players (for example, the Deep Fritz program, running on a laptop, beat reigning world champion Vladimir Kramnik without losing a single game in 2006), the best Go programs only manage to reach an intermediate amateur level. On the small 9×9 board, the computer fares better, and some programs now win a fraction of their 9×9 games against professional players . Human players generally achieve an intermediate amateur level by studying and playing regularly for a few years. Many in the field of artificial intelligence consider Go to require more elements that mimic human thought than chess. [76]

A finished beginner’s game on a 13×13 board. Go software can reach stronger levels on a smaller board size.

The reasons why computer programs do not play Go well are attributed to many qualities of the game, [77] including:

    • The number of spaces on the board is much larger (over five times the spaces on a chess board—361 vs. 64). On most turns there are many more possible moves in Go than in chess. Throughout most of the game, the number of legal moves stays at around 150–250 per turn, and rarely goes below 50 (in chess, the average number of moves is 37). [78] Because an exhaustive computer program for Go must calculate and compare every possible legal move in each ply (player turn), its ability to calculate the best plays is sharply reduced when there are a large number of possible moves. Most computer game algorithms, such as those for chess, compute several moves in advance. Given an average of 200 available moves through most of the game, for a computer to calculate its next move by exhaustively anticipating the next four moves of each possible play (two of its own and two of its opponent’s), it would have to consider more than 320 billion (3.2×1011) possible combinations. To exhaustively calculate the next eight moves, would require computing 512 quintillion (5.12×1020) possible combinations. As of June 2008, the most powerful supercomputer in the world, IBM’s « Roadrunner » distributed cluster, can sustain 1.02 petaflops. [79] [80] [81] At this rate, even given an exceedingly low estimate of 10 flops required to assess the value of one play of a stone, Roadrunner would require 138 hours, more than five days, to assess all possible combinations of the next eight moves in order to make a single play.

 

  • Unlike chess and Reversi, the placement of a single stone in the initial phase can affect the play of the game hundreds of moves later. For a computer to have a real advantage over a human, it would have to predict this influence, and from the example above, it would be completely unworkable to attempt to exhaustively analyze the next hundred moves to predict what a stone’s placement will do.

 

 

  • In capture-based games (such as chess), a position can often be evaluated relatively easily, such as by calculating who has a material advantage or more active pieces. [nb 15] In Go, there is often no easy way to evaluate a position. [75] [82] The number of stones on the board (material advantage) is only a weak indicator of the strength of a position, and a territorial advantage (more empty points surrounded) for one player might be compensated by the opponent’s strong positions and influence all over the board.

 

 

As an illustration, the greatest handicap normally given to a weaker opponent is 9 stones. It was not until August 2008 that a computer was able to win a game against a professional level player at this handicap. It was the Mogo program which scored said first victory in an exhibition game played during the US Go Congress. [83] [84]

Software assistance

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Main article: Go software

Beyond programs that play Go, there is an abundance of software available to support players of the game. This includes programs that can be used to view or edit game records and diagrams, programs that allow the user to search for patterns in the games of strong players, and programs that allow users to play against each other over the Internet. There are several file formats used to store game records, the most popular of which is SGF, short for Smart Game Format. Programs used for editing game records allow the user to record not only the moves, but also variations, commentary and further information on the game. [nb 16] Electronic databases can be used to study life and death situations, joseki, fuseki and games by a particular player. Programs are available that give players pattern searching options, which allow players to research positions by searching for high-level games in which similar situations occur. Such software generally lists common follow-up moves that have been played by professionals and gives statistics on win/loss ratio in opening situations. Internet-based Go servers allow access to competition with players all over the world. [nb 17] Such servers also allow easy access to professional teaching, with both teaching games and interactive game review being possible. [nb 18]

In culture and science

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Literature, television, and film

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Apart from technical literature and study material, Go and its strategies have been the subject of several works of fiction, such as The Master of Go by Nobel prize-winning author Yasunari Kawabata [nb 19] and The Girl Who Played Go by Shan Sa. Other books have used Go as a theme or minor plot device. For example, the 1979 novel Shibumi by Trevanian centers around the game and uses Go metaphors. [85] Go, referred to as Weiqi, features prominently in the 1986 Eric Van Lustbader novel Jian. Similarly, Go has been used as a subject or plot device in film, such as p, A Beautiful Mind and Tron: Legacy. Also in The Go Master, a biopic of Go professional Go Seigen. [86] [nb 20] In King Hu’s wuxia film The Valiant Ones, the characters are color-coded as go pieces (black or other dark shades for the Chinese, white for the Japanese invaders), go boards and stones are used by the characters to keep track of soldiers prior to battle, and the battles themselves are structured like a game of go. [87] Go is used as a device for criminal profiling in the pilot episode of Criminal Minds, « Extreme Aggressor ». Of particular note is the manga (Japanese comic book) and anime series Hikaru no Go, released in Japan in 1998, which had a large impact in popularizing Go among young players, both in Japan and—as translations were released—abroad. [88] [89] Also note that video game company Atari was named after Go. As Atari’s founder Nolan Bushnell was quoted as saying: « In Go, when you are about to capture an opponent’s piece, you politely warn them ‘Atari’. I felt that was a good aggressive name for a company. »

Psychology

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A 2004 review of literature by Gobet, de Voogt & Retschitzki [90] shows that relatively little scientific research has been carried out on the psychology of Go, compared with other traditional board games such as chess and Mancala. Computer Go research has shown that given the large search tree, knowledge and pattern recognition are more important in Go than in other strategy games, such as chess. [90] A study of the effects of age on Go-playing [91] has shown that mental decline is milder with strong players than with weaker players. According to the review of Gobet and colleagues, the pattern of brain activity observed with techniques such as PET and fMRI does not show large differences between Go and chess. On the other hand, a study by Xiangchuan Chen et al. [92] showed greater activation in the right hemisphere among Go players than among chess players. There is some evidence to suggest a correlation between playing board games and reduced risk of Alzheimer’s disease and dementia. [93]

See also

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Wikipedia Books are collections of articles that can be downloaded or ordered in print.
    • Go at the 2010 Asian Games

 

  • Go opening strategy

 

 

  • Go proverbs

 

 

  • Go variants and Games played with Go equipment

 

 

  • List of Go organizations

 

 

  • List of professional Go tournaments

 

 

Notes

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Footnotes

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    1. ^ The full Japanese name igo is derived from its Chinese name weiqi, which roughly translates as « board game of surrounding », see to go, it is sometimes capitalized or, in events sponsored by the Ing Foundation, spelled goe.

 

  • ^ Compare  » liberty », a small local government unit in medieval England – the « local area under control ».

 

 

  • ^ Exceptionally, in Japanese and Korean rules, empty points, even those surrounded by stones of a single colour, may count as neutral territory if some of them are alive by seki. See the section on « Life and Death » for seki.

 

 

  • ^ In game theoretical terms, seki positions are an example of a Nash equilibrium.

 

 

  • ^ See Overshoot in Western typography for similar subtle adjustment to create a uniform appearance.

 

 

  • ^ Roughly, one has the time to play the game and then a little time to finish it off. Time-wasting tactics are possible in Go, so that sudden death systems, in which time runs out at a predetermined point however many plays are in the game, are relatively unpopular (in the West).

 

 

  • ^ Literally in Japanese byoyomi means ‘reading of seconds’.

 

 

  • ^ Typically, players stop the clock, and the player in overtime sets his/her clock for the desired interval, counts out the required number of stones and sets the remaining stones out of reach, so as not to become confused. If twenty moves are made in time, the timer is reset to five minutes again.

 

 

  • ^ In other words, Canadian byoyomi is essentially a standard chess-style time control, based on N moves in a time period T, imposed after a main period is used up. It is possible to decrease T, or increase N, as each overtime period expires; but systems with constant T and N, for example 20 plays in 5 minutes, are widely used.

 

 

  • ^ A full explanation of the eternal life position can be found on ^ Kaku Takagawa toured Europe around 1970, and reported (Go Review) a general standard of amateur 4 dan. This is a good amateur level but no more than might be found in ordinary Asian clubs. Published current European ratings would suggest around 100 players stronger than that, with very few European 7 dans.

 

 

  • ^ European Go has been documented by Franco Pratesi, Eurogo (Florence 2003) in three volumes, up to 1920, 1920–1950, and 1950 and later.

 

 

  • ^ Whether or not a group is weak or strong refers to the ease with which it can be killed or made to live. See this ^ The number of board positions is at most 3361 (about 10172) since each position can be white, black, or vacant. There are at least 361! games (about 10768) since every permutation of the board positions corresponds to a game. See Go and mathematics for more details, which includes much larger estimates.

 

 

  • ^ While chess position evaluation is simpler than Go position evaluation, it is still more complicated than simply calculating material advantage or piece activity; pawn structure and king safety matter, as do the possibilities in further play. The complexity of the algorithm differs per engine.

 

 

  • ^ Lists of such programs may be found at ^ Lists of Go servers are kept at ^ The British Go Association provides a ^ A list of books can be found at ^ A list of films can de found at the edit] Citations
      1. ^ ^ ^ British Go Association, ^ NRICH Team, ^ Kim 1994 pp. 3–4

     

  • ^ Nihon Kiin, retrieved 2007-03-04

 

 

  • ^ Matthews, Charles, ^ Kim 1994 p. 12

 

 

  • ^ Kim 1994 p. 28

 

 

  • ^ Kim 1994 p. 30

 

 

  • ^ Kim 1994 pp 48–49

 

 

  • ^ a b c d e Kim 1994 pp. 144–147

 

 

  • ^ Fairbairn, John, ^ Hansen, Fred, a b c d Matthews 2002

 

 

  • ^ Potter 1985; Fairbairn 1995

 

 

  • ^ a b c Brooks 2007

 

 

  • ^ Potter 1984; Fairbairn 1995

 

 

  • ^ Fairbairn 1995

 

 

  • ^ Yang, Lihui; Deming An, Jessica Anderson Turner (2005). ISBN 978-1576078068.

 

 

  • ^ Masayoshi 2005; Lasker 1934

 

 

  • ^ Pickard 1989

 

 

  • ^ ^ Fairbairn 2000

 

 

  • ^ Nihon Kiin, retrieved 2007-11-02

 

 

  • ^ Nihon Kiin, retrieved 2007-11-02

 

 

  • ^ a b c GoGoD (Fairbairn & Hall) (2007), « Timeline 1600–1867 », History and Timelines

 

 

  • ^ GoGoD (Fairbairn & Hall) (2007), « Honinbo Dosaku », Articles on Famous Players

 

 

  • ^ GoGoD (Fairbairn & Hall) (2007), « Castle Games 1626–1863 », History and Timelines

 

 

  • ^ Pinckard, William (1992), History and Philosophy of Go in Bozulich, 2001 pp. 23–25

 

 

  • ^ a b ^ Bozulich, Richard, Yomiuri Shimbun, retrieved 2008-06-16

 

 

  • ^ British Go Association, ^ Peng & Hall 1996

 

 

  • ^ International Go Federation, ^ John Fairbairn, a b Fairbairn 1992 pp. 142–143

 

 

  • ^ a b c Fairbairn 1992 pp. 143–149

 

 

  • ^ a b c d e Fairbairn 1992 pp. 150–153

 

 

  • ^ Fairbairn 1992 pp. 153–155

 

 

  • ^ a b Fairbairn, John, ^ Nihon Ki-in, retrieved 2007-02-24

 

 

  • ^ ^ Bozulich 2001 pp. 92–93

 

 

  • ^ a b ^ ^ Go. The World’s Most Fascinating Game, Tokyo, Japan: Nihon Kiin, 1973, p. 188

 

 

  • ^ a b Cieply, Ales, ^ ^ ^ GoGoD (Fairbairn & Hall) (2007), A quick guide to pro tournaments

 

 

  • ^ GoGoD (Fairbairn & Hall) (2007), « History of Komi », History and Timelines

 

 

  • ^ a b Jasiek, Robert (2001), ^ Fairbairn, John, ^ ^ Fairbairn, John, ^ Fairbairn, John, ^ ^ Kim, Janice, ^ Matthews, Charles, ^ ^ Shotwell, Peter (2003), Go! More Than a Game, Tuttle Publishing, ISBN 0-8048-3475-X

 

 

  • ^ ^ Kim 1994 pp. 80–98

 

 

  • ^ Kim 1994 pp. 88–90

 

 

  • ^ Kim 1994 pp. 91–92

 

 

  • ^ Kim 1994 pp. 93–94

 

 

  • ^ Nakayama, Noriyuki (1984), « Memories of Kitani », The Treasure Chest Enigma, Slate & Shell, pp. 16–19, ISBN 1-932001-27-1

 

 

  • ^ a b van Zeijst, Rob, Yomiuri Shimbun, retrieved 2008-06-09

 

 

  • ^ ^ Otake, Hideo (2002), Opening Theory Made Easy, Kiseido Publishing Company, ISBN 490657436X

 

 

  • ^ Ishida, Yoshio (1977), Dictionary of Basic Joseki, Kiseido Publishing Company

 

 

  • ^ a b Stern, David (2008-02-01), University of Cambridge, retrieved 2008-12-04

 

 

  • ^ Johnson, George (1997-07-29), The New York Times, retrieved 2008-06-16

 

 

  • ^ ^ Keene, Raymond; Levy, David (1991), How to beat your chess computer, Batsford Books, p. 85

 

 

  • ^ Sharon Gaudin (2008-06-09). ^ CNET News.com.

 

 

  • ^ ^ Fellows, Christopher (2006-00-00), Cornell University, retrieved 2008-12-19

 

 

  • ^ ^ ^ McDonald, Brian (2002) [1995], ^ Scott, A.O. (March 14, 2007), The New York Times, retrieved 2008-06-16

 

 

  • ^ Ng Ho (1998). « King Hu and the Aesthetics of Space ». In Teo, Stephen. Transcending the Times:King Hu & Eileen Chan. Hong Kong International Film Festival. Hong Kong: Provisional Urban Council of Hong Kong. p. 45.

 

 

  • ^ Shimatsuka, Yoko, ^ Scanlon, Charles (Thursday, 1 August 2002, 03:35 GMT 04:35 UK). a b Gobet, F; de Voogt, A. J; Retschitzki, J (2004), ISBN 1841693367

 

 

  • ^ Masunaga, H; Horn, J. (2001), « Expertise and age-related changes in components of intelligence », Psychology and Aging 16 (16): 293–311, doi: ^ Chen et al. (2003), doi: ^ Verghese et al.; Lipton, RB; Katz, MJ; Hall, CB; Derby, CA; Kuslansky, G; Ambrose, AF; Sliwinski, M et al. (2003), doi: PMID edit] References
      • Bozulich, Richard (2001), The Go Player’s Almanac (2nd ed.), Kiseido Publishing Company, ISBN 4-906574-40-8

     

  • Brooks, E Bruce (2007), Fairbairn, John (1992), A Survey of the best in Go Equipment in Bozulich 2001—pp. 142–155

 

 

  • Fairbairn, John (1995), Fairbairn, John (2000), ISBN 0-9644796-1-3

 

 

  • Lasker, Edward (1960) [1934], Go and Go-Moku, Courier Dover Publications, ISBN 0486206130

 

 

  • Masayoshi, Shirakawa (2005), A Journey In Search of the Origins of Go, Yutopian Enterprises, ISBN 1889554987

 

 

  • Matthews, Charles (September 2002), ISBN 9784906574308, retrieved 2007-11-02

 

 

  • Potter, Donald L. (1984), Go World (Tokyo: Ishi Press) (37): 16–18, retrieved 2007-11-02

 

 

  • Potter, Donald L. (1985), Go World (Tokyo: Ishi Press) (42): 19–21, retrieved 2007-11-02

 

Further reading

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Introductory books:

    • Bradley, Milton N. Go for Kids, Yutopian Enterprises, Santa Monica, 2001 ISBN 978-1-889554-74-7.

 

  • Cho, Chikun. Go: A Complete Introduction to the Game, Kiseido Publishers, Tokyo, 1997, ISBN 978-4-906574-50-6.

 

 

  • Cobb, William. The Book of Go, Sterling Publishers, 2002, ISBN 978-0-8069-2729-9.

 

 

  • Iwamoto, Kaoru. Go for Beginners, Pantheon, New York, 1977, ISBN 978-0-394-73331-9.

 

 

  • Kim, Janice, and Jeong Soo-hyun. Learn to Play Go series, five volumes: Good Move Press, Sheboygan, Wisconsin, second edition, 1997. ISBN 0-9644796-1-3.

 

 

  • Matthews, Charles. Teach Yourself Go, McGraw-Hill, 2004, ISBN 978-0-07-142977-1.

 

 

  • Shotwell, Peter. Go! More than a Game, Tuttle Publishing, Boston, 2003. ISBN 0-8048-3475-X.

 

 

Historical interest:

    • Boorman, Scott A. (1969), The Protracted Game: A Wei Ch’i Interpretation of Maoist Revolutionary Strategy, New York, NY: Oxford University Press, ISBN 9780195014938

 

  • De Havilland, Augustus Walter (1910), The ABC of Go: The National War Game of Japan, Yokohama, Kelly & Walsh, OCLC Korschelt, Oscar (1966), The Theory and Practice of Go, C.E. Tuttle Co, ISBN 9780804805728

 

 

  • Smith, Arthur (1956), The Game of Go: The National Game of Japan, C.E. Tuttle Co, OCLC edit] External links
    Wikibooks has a book on the topic of 

    Wikiquote has a collection of quotations related to: Wikisource has the text of the 1911 Encyclopædia Britannica article Go.

     

  • European Go Federation (EGF), at eurogofed.org

 

 

 

 

 

 

  • Go Bibliography, comprehensive bibliography – reviews, cover images, details, at gobooks.nemir.org

 

 

  • Go in Print, list and reviews of English Go books, at usgo.org

 

 

  • Go Servers, list of servers for playing on-line at Sensei’s Library, at senseis.xmp.net

 

 

  • Goproblems.com, open database of interactive Go problems, at goproblems.com

 

 

 

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